Thanks @felmue , I did notice that too so I used continuity tester to see if andy of the RS-485 terminal screws were directly connected to the header pins that connect to the Atom's 33/23 pins I did't detect any continuity. I want to connect a Nextion Display that uses a Serial connection to the Atom Switch and was hoping to utilize Pins 33/23. I'm thinking I may need to purchase something like the MAX485 RS-485 module to attach to the Nextion display and run my serial connection over this RS-485 connection. Think I have some reading to do. ;)